Watching brief A programme of eight windowless borehole samples (WS01-WS08), two window samples (BH01-2) and four hand dug test pits (HP01-4) was undertaken across the site. The depths of significant deposits were recorded to identify the thickness of made-ground deposits, archaeological horizons and the level at which natural geology was encountered.Evaluation A total of three trenches were excavated by an eight-ton tracked mechanical excavator using a toothless bucket under the direct supervision of an archaeologist over a period of six days. The trenches were targeted at the edge of the abbey precinct (Trenches 1 and 2) and in the location of the abbey fish ponds (Trench 3). Oxford Archaeology was commissioned by Silver/A2 Dominion to undertake an archaeological watching brief on geotechnical investigations for an area of land at Gibbs Crescent, Oxford. The site falls within the administrative district of Oxford City Council and is located within the Osney Town conservation area. The site is centred on NGR SP 50543 05814. The site has the potential to contain previously unidentified Saxon and medieval deposits. Previous excavations within the area have identified a possible Saxon cemetery to the north of the site and the site itself falls within the southern area of the medieval remains of Osney Abbey precinct. The site has a high potential to contain archaeological remains associated with Osney Abbey. A programme of boreholes and hand dug test pits was monitored in order to help clarify the archaeological potential of the site and determine whether the site contained significant levels of made-ground, which may act as a buffer between the proposed development works and any archaeological deposits that may be present within the footprint of the scheme. The watching brief found natural gravel, which was reached within the geotechnical boreholes between 3.85-2.6m below ground level. This was overlain by 2m of organic and alluvial deposits that have good potential to contain undisturbed archaeological and palaeoenvironmental remains. One early medieval sherd of pottery was recovered from an alluvial deposit at 1.70m within WS04, where the abbey fish ponds were originally located. Evidence of potential ground make-up deposits were found within WS01, where the abbey precinct was originally located. Most of the site was sealed by 1.2-2.4m of modern made-ground deposits, dating from the construction of the railway during the 19th century. The results of the watching brief will inform the proposed foundation design to help minimise the impacts on the archaeological resource. Based on the current proposed designs it is likely that any underlying archaeological deposits could remain unaffected by the proposed development and be preserved in-situ. Further archaeological evaluation and mitigation works may be required during later stages of the project in relation to specific localised impacts. In May 2019 Oxford Archaeology undertook an archaeological evaluation at Gibbs Crescent, Osney, Oxford in advance of redevelopment proposals. Three trenches were excavated through alluvial and make-up deposits associated with the medieval Osney Abbey. Remains dating to the time of the abbey were encountered within Trenches 1 and 2. An alluvial sequence overlying gravel was identified in the base of the trenches, overlain by medieval reclamation deposits. The remains of a potential hearth were identified on this surface at 1.4m below ground level in Trench 1 and potential structural remains 1.6m below ground level in Trench 2. The garden soils recorded above the reclamation surface dated to after the dissolution. Overlying the whole site were modern deposits relating to either the nearby railway or the construction of Gibbs Crescent itself.
Champness et al. (Tue,) studied this question.